// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2012,2013 Infineon Technologies * * Authors: * Peter Huewe <[email protected]> * * Device driver for TCG/TCPA TPM (trusted platform module). * Specifications at www.trustedcomputinggroup.org * * This device driver implements the TPM interface as defined in * the TCG TPM Interface Spec version 1.2, revision 1.0 and the * Infineon I2C Protocol Stack Specification v0.20. * * It is based on the original tpm_tis device driver from Leendert van * Dorn and Kyleen Hall. */ #include <linux/i2c.h> #include <linux/module.h> #include <linux/wait.h> #include "tpm.h" #define TPM_I2C_INFINEON_BUFSIZE … /* max. number of iterations after I2C NAK */ #define MAX_COUNT … #define SLEEP_DURATION_LOW … #define SLEEP_DURATION_HI … /* max. number of iterations after I2C NAK for 'long' commands * we need this especially for sending TPM_READY, since the cleanup after the * transtion to the ready state may take some time, but it is unpredictable * how long it will take. */ #define MAX_COUNT_LONG … #define SLEEP_DURATION_LONG_LOW … #define SLEEP_DURATION_LONG_HI … /* After sending TPM_READY to 'reset' the TPM we have to sleep even longer */ #define SLEEP_DURATION_RESET_LOW … #define SLEEP_DURATION_RESET_HI … /* we want to use usleep_range instead of msleep for the 5ms TPM_TIMEOUT */ #define TPM_TIMEOUT_US_LOW … #define TPM_TIMEOUT_US_HI … /* expected value for DIDVID register */ #define TPM_TIS_I2C_DID_VID_9635 … #define TPM_TIS_I2C_DID_VID_9645 … enum i2c_chip_type { … }; struct tpm_inf_dev { … }; static struct tpm_inf_dev tpm_dev; /* * iic_tpm_read() - read from TPM register * @addr: register address to read from * @buffer: provided by caller * @len: number of bytes to read * * Read len bytes from TPM register and put them into * buffer (little-endian format, i.e. first byte is put into buffer[0]). * * NOTE: TPM is big-endian for multi-byte values. Multi-byte * values have to be swapped. * * NOTE: We can't unfortunately use the combined read/write functions * provided by the i2c core as the TPM currently does not support the * repeated start condition and due to it's special requirements. * The i2c_smbus* functions do not work for this chip. * * Return -EIO on error, 0 on success. */ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len) { … } static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len, unsigned int sleep_low, unsigned int sleep_hi, u8 max_count) { … } /* * iic_tpm_write() - write to TPM register * @addr: register address to write to * @buffer: containing data to be written * @len: number of bytes to write * * Write len bytes from provided buffer to TPM register (little * endian format, i.e. buffer[0] is written as first byte). * * NOTE: TPM is big-endian for multi-byte values. Multi-byte * values have to be swapped. * * NOTE: use this function instead of the iic_tpm_write_generic function. * * Return -EIO on error, 0 on success */ static int iic_tpm_write(u8 addr, u8 *buffer, size_t len) { … } /* * This function is needed especially for the cleanup situation after * sending TPM_READY * */ static int iic_tpm_write_long(u8 addr, u8 *buffer, size_t len) { … } enum tis_access { … }; enum tis_status { … }; enum tis_defaults { … }; #define TPM_ACCESS(l) … #define TPM_STS(l) … #define TPM_DATA_FIFO(l) … #define TPM_DID_VID(l) … static bool check_locality(struct tpm_chip *chip, int loc) { … } /* implementation similar to tpm_tis */ static void release_locality(struct tpm_chip *chip, int loc, int force) { … } static int request_locality(struct tpm_chip *chip, int loc) { … } static u8 tpm_tis_i2c_status(struct tpm_chip *chip) { … } static void tpm_tis_i2c_ready(struct tpm_chip *chip) { … } static ssize_t get_burstcount(struct tpm_chip *chip) { … } static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout, int *status) { … } static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) { … } static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 *buf, size_t count) { … } static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len) { … } static bool tpm_tis_i2c_req_canceled(struct tpm_chip *chip, u8 status) { … } static const struct tpm_class_ops tpm_tis_i2c = …; static int tpm_tis_i2c_init(struct device *dev) { … } static const struct i2c_device_id tpm_tis_i2c_table[] = …; MODULE_DEVICE_TABLE(i2c, tpm_tis_i2c_table); #ifdef CONFIG_OF static const struct of_device_id tpm_tis_i2c_of_match[] = …; MODULE_DEVICE_TABLE(of, tpm_tis_i2c_of_match); #endif static SIMPLE_DEV_PM_OPS(tpm_tis_i2c_ops, tpm_pm_suspend, tpm_pm_resume); static int tpm_tis_i2c_probe(struct i2c_client *client) { … } static void tpm_tis_i2c_remove(struct i2c_client *client) { … } static struct i2c_driver tpm_tis_i2c_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_VERSION(…) …; MODULE_LICENSE(…) …;
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