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/*
* STMicroelectronics TPM I2C Linux driver for TPM ST33ZP24
* Copyright (C) 2009 - 2016 STMicroelectronics
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/of_irq.h>
#include <linux/of_gpio.h>
#include <linux/acpi.h>
#include <linux/tpm.h>
#include <linux/platform_data/st33zp24.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];
int io_lpcpd;
};
/*
* 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,
};
static const struct acpi_gpio_params lpcpd_gpios = { 1, 0, false };
static const struct acpi_gpio_mapping acpi_st33zp24_gpios[] = {
{ "lpcpd-gpios", &lpcpd_gpios, 1 },
{},
};
static int st33zp24_i2c_acpi_request_resources(struct i2c_client *client)
{
struct tpm_chip *chip = i2c_get_clientdata(client);
struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
struct st33zp24_i2c_phy *phy = tpm_dev->phy_id;
struct gpio_desc *gpiod_lpcpd;
struct device *dev = &client->dev;
int ret;
ret = devm_acpi_dev_add_driver_gpios(dev, acpi_st33zp24_gpios);
if (ret)
return ret;
/* Get LPCPD GPIO from ACPI */
gpiod_lpcpd = devm_gpiod_get(dev, "lpcpd", GPIOD_OUT_HIGH);
if (IS_ERR(gpiod_lpcpd)) {
dev_err(&client->dev,
"Failed to retrieve lpcpd-gpios from acpi.\n");
phy->io_lpcpd = -1;
/*
* lpcpd pin is not specified. This is not an issue as
* power management can be also managed by TPM specific
* commands. So leave with a success status code.
*/
return 0;
}
phy->io_lpcpd = desc_to_gpio(gpiod_lpcpd);
return 0;
}
static int st33zp24_i2c_of_request_resources(struct i2c_client *client)
{
struct tpm_chip *chip = i2c_get_clientdata(client);
struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
struct st33zp24_i2c_phy *phy = tpm_dev->phy_id;
struct device_node *pp;
int gpio;
int ret;
pp = client->dev.of_node;
if (!pp) {
dev_err(&client->dev, "No platform data\n");
return -ENODEV;
}
/* Get GPIO from device tree */
gpio = of_get_named_gpio(pp, "lpcpd-gpios", 0);
if (gpio < 0) {
dev_err(&client->dev,
"Failed to retrieve lpcpd-gpios from dts.\n");
phy->io_lpcpd = -1;
/*
* lpcpd pin is not specified. This is not an issue as
* power management can be also managed by TPM specific
* commands. So leave with a success status code.
*/
return 0;
}
/* GPIO request and configuration */
ret = devm_gpio_request_one(&client->dev, gpio,
GPIOF_OUT_INIT_HIGH, "TPM IO LPCPD");
if (ret) {
dev_err(&client->dev, "Failed to request lpcpd pin\n");
return -ENODEV;
}
phy->io_lpcpd = gpio;
return 0;
}
static int st33zp24_i2c_request_resources(struct i2c_client *client)
{
struct tpm_chip *chip = i2c_get_clientdata(client);
struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
struct st33zp24_i2c_phy *phy = tpm_dev->phy_id;
struct st33zp24_platform_data *pdata;
int ret;
pdata = client->dev.platform_data;
if (!pdata) {
dev_err(&client->dev, "No platform data\n");
return -ENODEV;
}
/* store for late use */
phy->io_lpcpd = pdata->io_lpcpd;
if (gpio_is_valid(pdata->io_lpcpd)) {
ret = devm_gpio_request_one(&client->dev,
pdata->io_lpcpd, GPIOF_OUT_INIT_HIGH,
"TPM IO_LPCPD");
if (ret) {
dev_err(&client->dev, "Failed to request lpcpd pin\n");
return ret;
}
}
return 0;
}
/*
* st33zp24_i2c_probe initialize the TPM device
* @param: client, the i2c_client drescription (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,
const struct i2c_device_id *id)
{
int ret;
struct st33zp24_platform_data *pdata;
struct st33zp24_i2c_phy *phy;
if (!client) {
pr_info("%s: i2c client is NULL. Device not accessible.\n",
__func__);
return -ENODEV;
}
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;
pdata = client->dev.platform_data;
if (!pdata && client->dev.of_node) {
ret = st33zp24_i2c_of_request_resources(client);
if (ret)
return ret;
} else if (pdata) {
ret = st33zp24_i2c_request_resources(client);
if (ret)
return ret;
} else if (ACPI_HANDLE(&client->dev)) {
ret = st33zp24_i2c_acpi_request_resources(client);
if (ret)
return ret;
}
return st33zp24_probe(phy, &i2c_phy_ops, &client->dev, client->irq,
phy->io_lpcpd);
}
/*
* st33zp24_i2c_remove remove the TPM device
* @param: client, the i2c_client description (TPM I2C description).
* @return: 0 in case of success.
*/
static int st33zp24_i2c_remove(struct i2c_client *client)
{
struct tpm_chip *chip = i2c_get_clientdata(client);
int ret;
ret = st33zp24_remove(chip);
if (ret)
return ret;
return 0;
}
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[] = {
{ .compatible = "st,st33zp24-i2c", },
{}
};
MODULE_DEVICE_TABLE(of, of_st33zp24_i2c_match);
static const struct acpi_device_id st33zp24_i2c_acpi_match[] = {
{"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");
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