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/* Copyright 2015 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/*
* This defines the interface functions for TPM SPI Hardware Protocol. The SPI
* master reads or writes between 1 and 64 bytes to a register designated by a
* 24-bit address. There is no provision for error reporting at this level.
*/
#ifndef __CROS_EC_TPM_REGISTERS_H
#define __CROS_EC_TPM_REGISTERS_H
#include <stdint.h>
#include "common.h"
/* The SPI master is writing data into a TPM register. */
void tpm_register_put(uint32_t regaddr,
const uint8_t *data, uint32_t data_size);
/* The SPI master is reading data from a TPM register. */
void tpm_register_get(uint32_t regaddr, uint8_t *dest, uint32_t data_size);
/* Get the current value of the burst size field of the status register. */
size_t tpm_get_burst_size(void);
/*
* Register functions to start and stop TPM communications layer. The
* communications layer should be kept down while TPM is being reset.
*/
typedef void (*interface_control_func)(void);
void tpm_register_interface(interface_control_func interface_start,
interface_control_func interface_stop);
/*
* This requests the TPM task to reset itself.
*
* If wait_until_done is false, it returns EC_SUCCESS immediately. Otherwise it
* returns EC_SUCCESS after the reset has completed, or an error code on
* failure.
*
* If wipe_nvmem_first is true, the caller is expected to keep the rest of the
* system in reset until TPM wipeout is completed.
*/
int tpm_reset_request(int wait_until_done, int wipe_nvmem_first);
/*
* Tell the TPM task to re-enable nvmem commits.
*
* NOTE: This function is NOT to be used freely, but only meant to be used in
* exceptional cases such as unlocking the console following a TPM wipe.
*/
void tpm_reinstate_nvmem_commits(void);
/*
* To be called by functions running on the TPM task context. Returns
* EC_SUCCESS on successful reset.
*/
int tpm_sync_reset(int wipe_first);
/*
* It shuts down the tpm interface, until next tpm reset event.
*/
void tpm_stop(void);
/*
* This structure describes the header of all commands and responses sent and
* received over TPM FIFO.
*
* Note that all fields are stored in the network (big endian) byte order.
*/
struct tpm_cmd_header {
uint16_t tag;
uint32_t size;
uint32_t command_code;
uint16_t subcommand_code; /* Not a standard field. */
} __packed;
/*
* This function allows to process a TPM command coming from elsewhere, not
* from the communications interface.
*
* A common use case would be making cryptographic calculation on task
* contexts where stack the size is not large enough, for instance console
* commands. This function will block to let the TPM task a chance to run to
* execute the command and return the result in the same buffer.
*
* @param tpmh pointer to a buffer containing a marshalled TPM command, if it
* arrived over the communications channel. One of the header
* fields defines the command size.
*
* @param buffer_size the size of the buffer pointed to by tpmh - tells the
* TPM task how much room there is to store the response.
*
* Command execution result is reported in the response body.
*
* The extension command handler will consider all these commands to come from
* the USB interface, since the only current users for this are console
* commands.
*/
void tpm_alt_extension(struct tpm_cmd_header *tpmh, size_t buffer_size);
/*
* The only TPM2 command we care about on the driver level, see
* crosbug.com/p/55667 for detals.
*/
#define TPM2_PCR_Read 0x0000017e
#define TPM2_Startup 0x00000144
/* TPM mode */
enum tpm_modes {
TPM_MODE_ENABLED_TENTATIVE = 0,
TPM_MODE_ENABLED = 1,
TPM_MODE_DISABLED = 2,
TPM_MODE_MAX,
};
/*
* This function returns the current TPM_MODE value.
*/
enum tpm_modes get_tpm_mode(void);
#endif /* __CROS_EC_TPM_REGISTERS_H */