// SPDX-License-Identifier: GPL-2.0-or-later /* * STMicroelectronics TPM I2C Linux driver for TPM ST33ZP24 * Copyright (C) 2009 - 2016 STMicroelectronics */ #include <linux/module.h> #include <linux/i2c.h> #include <linux/of.h> #include <linux/acpi.h> #include <linux/tpm.h> #include "../tpm.h" #include "st33zp24.h" #define TPM_DUMMY_BYTE 0xAA struct st33zp24_i2c_phy { struct i2c_client *client; u8 buf[ST33ZP24_BUFSIZE + 1]; }; /* * write8_reg * Send byte to the TIS register according to the ST33ZP24 I2C protocol. * @param: tpm_register, the tpm tis register where the data should be written * @param: tpm_data, the tpm_data to write inside the tpm_register * @param: tpm_size, The length of the data * @return: Returns negative errno, or else the number of bytes written. */ static int write8_reg(void *phy_id, u8 tpm_register, u8 *tpm_data, int tpm_size) { struct st33zp24_i2c_phy *phy = phy_id; phy->buf[0] = tpm_register; memcpy(phy->buf + 1, tpm_data, tpm_size); return i2c_master_send(phy->client, phy->buf, tpm_size + 1); } /* write8_reg() */ /* * read8_reg * Recv byte from the TIS register according to the ST33ZP24 I2C protocol. * @param: tpm_register, the tpm tis register where the data should be read * @param: tpm_data, the TPM response * @param: tpm_size, tpm TPM response size to read. * @return: number of byte read successfully: should be one if success. */ static int read8_reg(void *phy_id, u8 tpm_register, u8 *tpm_data, int tpm_size) { struct st33zp24_i2c_phy *phy = phy_id; u8 status = 0; u8 data; data = TPM_DUMMY_BYTE; status = write8_reg(phy, tpm_register, &data, 1); if (status == 2) status = i2c_master_recv(phy->client, tpm_data, tpm_size); return status; } /* read8_reg() */ /* * st33zp24_i2c_send * Send byte to the TIS register according to the ST33ZP24 I2C protocol. * @param: phy_id, the phy description * @param: tpm_register, the tpm tis register where the data should be written * @param: tpm_data, the tpm_data to write inside the tpm_register * @param: tpm_size, the length of the data * @return: number of byte written successfully: should be one if success. */ static int st33zp24_i2c_send(void *phy_id, u8 tpm_register, u8 *tpm_data, int tpm_size) { return write8_reg(phy_id, tpm_register | TPM_WRITE_DIRECTION, tpm_data, tpm_size); } /* * st33zp24_i2c_recv * Recv byte from the TIS register according to the ST33ZP24 I2C protocol. * @param: phy_id, the phy description * @param: tpm_register, the tpm tis register where the data should be read * @param: tpm_data, the TPM response * @param: tpm_size, tpm TPM response size to read. * @return: number of byte read successfully: should be one if success. */ static int st33zp24_i2c_recv(void *phy_id, u8 tpm_register, u8 *tpm_data, int tpm_size) { return read8_reg(phy_id, tpm_register, tpm_data, tpm_size); } static const struct st33zp24_phy_ops i2c_phy_ops = { .send = st33zp24_i2c_send, .recv = st33zp24_i2c_recv, }; /* * st33zp24_i2c_probe initialize the TPM device * @param: client, the i2c_client description (TPM I2C description). * @param: id, the i2c_device_id struct. * @return: 0 in case of success. * -1 in other case. */ static int st33zp24_i2c_probe(struct i2c_client *client) { struct st33zp24_i2c_phy *phy; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { dev_info(&client->dev, "client not i2c capable\n"); return -ENODEV; } phy = devm_kzalloc(&client->dev, sizeof(struct st33zp24_i2c_phy), GFP_KERNEL); if (!phy) return -ENOMEM; phy->client = client; return st33zp24_probe(phy, &i2c_phy_ops, &client->dev, client->irq); } /* * st33zp24_i2c_remove remove the TPM device * @param: client, the i2c_client description (TPM I2C description). * @return: 0 in case of success. */ static void st33zp24_i2c_remove(struct i2c_client *client) { struct tpm_chip *chip = i2c_get_clientdata(client); st33zp24_remove(chip); } static const struct i2c_device_id st33zp24_i2c_id[] = { { TPM_ST33_I2C }, {} }; MODULE_DEVICE_TABLE(i2c, st33zp24_i2c_id); static const struct of_device_id of_st33zp24_i2c_match[] __maybe_unused = { { .compatible = "st,st33zp24-i2c", }, {} }; MODULE_DEVICE_TABLE(of, of_st33zp24_i2c_match); static const struct acpi_device_id st33zp24_i2c_acpi_match[] __maybe_unused = { {"SMO3324"}, {} }; MODULE_DEVICE_TABLE(acpi, st33zp24_i2c_acpi_match); static SIMPLE_DEV_PM_OPS(st33zp24_i2c_ops, st33zp24_pm_suspend, st33zp24_pm_resume); static struct i2c_driver st33zp24_i2c_driver = { .driver = { .name = TPM_ST33_I2C, .pm = &st33zp24_i2c_ops, .of_match_table = of_match_ptr(of_st33zp24_i2c_match), .acpi_match_table = ACPI_PTR(st33zp24_i2c_acpi_match), }, .probe = st33zp24_i2c_probe, .remove = st33zp24_i2c_remove, .id_table = st33zp24_i2c_id }; module_i2c_driver(st33zp24_i2c_driver); MODULE_AUTHOR("TPM support <TPMsupport@list.st.com>"); MODULE_DESCRIPTION("STM TPM 1.2 I2C ST33 Driver"); MODULE_VERSION("1.3.0"); MODULE_LICENSE("GPL");