| /* |
| * STMicroelectronics TPM I2C Linux driver for TPM ST33ZP24 |
| * Copyright (C) 2009 - 2016 STMicroelectronics |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #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[TPM_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 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; |
| |
| /* Get LPCPD GPIO from ACPI */ |
| gpiod_lpcpd = devm_gpiod_get_index(dev, "TPM IO LPCPD", 1, |
| 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); |
| |
| return 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[] = { |
| { .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"); |