/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (c) 2013 The Chromium OS Authors.
* Coypright (c) 2013 Guntermann & Drunck GmbH
*/
#ifndef __TPM_COMMON_H
#define __TPM_COMMON_H
enum tpm_duration {
TPM_SHORT = 0,
TPM_MEDIUM = 1,
TPM_LONG = 2,
TPM_UNDEFINED,
TPM_DURATION_COUNT,
};
/*
* Here is a partial implementation of TPM commands. Please consult TCG Main
* Specification for definitions of TPM commands.
*/
#define TPM_HEADER_SIZE 10
/* Max buffer size supported by our tpm */
#define TPM_DEV_BUFSIZE 1260
/**
* struct tpm_chip_priv - Information about a TPM, stored by the uclass
*
* These values must be set up by the device's probe() method before
* communcation is attempted. If the device has an xfer() method, this is
* not needed. There is no need to set up @buf.
*
* @duration_ms: Length of each duration type in milliseconds
* @retry_time_ms: Time to wait before retrying receive
* @pcr_count: Number of PCR per bank
* @pcr_select_min: Minimum size in bytes of the pcrSelect array
* @buf: Buffer used during the exchanges with the chip
*/
struct tpm_chip_priv {
uint duration_ms[TPM_DURATION_COUNT];
uint retry_time_ms;
#if defined(CONFIG_TPM_V2)
uint pcr_count;
uint pcr_select_min;
#endif
u8 buf[TPM_DEV_BUFSIZE + sizeof(u8)]; /* Max buffer size + addr */
};
/**
* struct tpm_ops - low-level TPM operations
*
* These are designed to avoid loops and delays in the driver itself. These
* should be handled in the uclass.
*
* In gneral you should implement everything except xfer(). Where you need
* complete control of the transfer, then xfer() can be provided and will
* override the other methods.
*
* This interface is for low-level TPM access. It does not understand the
* concept of localities or the various TPM messages. That interface is
* defined in the functions later on in this file, but they all translate
* to bytes which are sent and received.
*/
struct tpm_ops {
/**
* open() - Request access to locality 0 for the caller
*
* After all commands have been completed the caller should call
* close().
*
* @dev: Device to close
* @return 0 ok OK, -ve on error
*/
int (*open)(struct udevice *dev);
/**
* close() - Close the current session
*
* Releasing the locked locality. Returns 0 on success, -ve 1 on
* failure (in case lock removal did not succeed).
*
* @dev: Device to close
* @return 0 ok OK, -ve on error
*/
int (*close)(struct udevice *dev);
/**
* get_desc() - Get a text description of the TPM
*
* @dev: Device to check
* @buf: Buffer to put the string
* @size: Maximum size of buffer
* @return length of string, or -ENOSPC it no space
*/
int (*get_desc)(struct udevice *dev, char *buf, int size);
/**
* send() - send data to the TPM
*
* @dev: Device to talk to
* @sendbuf: Buffer of the data to send
* @send_size: Size of the data to send
*
* Returns 0 on success or -ve on failure.
*/
int (*send)(struct udevice *dev, const u8 *sendbuf, size_t send_size);
/**
* recv() - receive a response from the TPM
*
* @dev: Device to talk to
* @recvbuf: Buffer to save the response to
* @max_size: Maximum number of bytes to receive
*
* Returns number of bytes received on success, -EAGAIN if the TPM
* response is not ready, -EINTR if cancelled, or other -ve value on
* failure.
*/
int (*recv)(struct udevice *dev, u8 *recvbuf, size_t max_size);
/**
* cleanup() - clean up after an operation in progress
*
* This is called if receiving times out. The TPM may need to abort
* the current transaction if it did not complete, and make itself
* ready for another.
*
* @dev: Device to talk to
*/
int (*cleanup)(struct udevice *dev);
/**
* xfer() - send data to the TPM and get response
*
* This method is optional. If it exists it is used in preference
* to send(), recv() and cleanup(). It should handle all aspects of
* TPM communication for a single transfer.
*
* @dev: Device to talk to
* @sendbuf: Buffer of the data to send
* @send_size: Size of the data to send
* @recvbuf: Buffer to save the response to
* @recv_size: Pointer to the size of the response buffer
*
* Returns 0 on success (and places the number of response bytes at
* recv_size) or -ve on failure.
*/
int (*xfer)(struct udevice *dev, const u8 *sendbuf, size_t send_size,
u8 *recvbuf, size_t *recv_size);
};
#define tpm_get_ops(dev) ((struct tpm_ops *)device_get_ops(dev))
#define MAKE_TPM_CMD_ENTRY(cmd) \
U_BOOT_CMD_MKENT(cmd, 0, 1, do_tpm_ ## cmd, "", "")
#define TPM_COMMAND_NO_ARG(cmd) \
int do_##cmd(cmd_tbl_t *cmdtp, int flag, \
int argc, char * const argv[]) \
{ \
if (argc != 1) \
return CMD_RET_USAGE; \
return report_return_code(cmd()); \
}
/**
* tpm_get_desc() - Get a text description of the TPM
*
* @dev: Device to check
* @buf: Buffer to put the string
* @size: Maximum size of buffer
* @return length of string, or -ENOSPC it no space
*/
int tpm_get_desc(struct udevice *dev, char *buf, int size);
/**
* tpm_xfer() - send data to the TPM and get response
*
* This first uses the device's send() method to send the bytes. Then it calls
* recv() to get the reply. If recv() returns -EAGAIN then it will delay a
* short time and then call recv() again.
*
* Regardless of whether recv() completes successfully, it will then call
* cleanup() to finish the transaction.
*
* Note that the outgoing data is inspected to determine command type
* (ordinal) and a timeout is used for that command type.
*
* @sendbuf - buffer of the data to send
* @send_size size of the data to send
* @recvbuf - memory to save the response to
* @recv_len - pointer to the size of the response buffer
*
* Returns 0 on success (and places the number of response bytes at
* recv_len) or -ve on failure.
*/
int tpm_xfer(struct udevice *dev, const u8 *sendbuf, size_t send_size,
u8 *recvbuf, size_t *recv_size);
/**
* Initialize TPM device. It must be called before any TPM commands.
*
* @return 0 on success, non-0 on error.
*/
int tpm_init(void);
/**
* Retrieve the array containing all the commands.
*
* @return a cmd_tbl_t array.
*/
cmd_tbl_t *get_tpm_commands(unsigned int *size);
#endif /* __TPM_COMMON_H */