blob: 661574bb0acf59a8f623bc20267901021e8f9b6a [file] [log] [blame]
// 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, 0},
{}
};
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");