blob: 205d7a5d97db9a5ac9e5f5dd59e0ff05f82100dd [file] [log] [blame]
/*
* Copyright (C) 2013 Guntermann & Drunck, GmbH
*
* Written by Dirk Eibach <eibach@gdsys.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <tpm.h>
#include <i2c.h>
#include <asm/unaligned.h>
#define ATMEL_TPM_TIMEOUT_MS 5000 /* sufficient for anything but
generating/exporting keys */
/*
* tis_init()
*
* Initialize the TPM device. Returns 0 on success or -1 on
* failure (in case device probing did not succeed).
*/
int tis_init(void)
{
return 0;
}
/*
* tis_open()
*
* Requests access to locality 0 for the caller. After all commands have been
* completed the caller is supposed to call tis_close().
*
* Returns 0 on success, -1 on failure.
*/
int tis_open(void)
{
return 0;
}
/*
* tis_close()
*
* terminate the currect session with the TPM by releasing the locked
* locality. Returns 0 on success of -1 on failure (in case lock
* removal did not succeed).
*/
int tis_close(void)
{
return 0;
}
/*
* tis_sendrecv()
*
* Send the requested data to the TPM and then try to get its response
*
* @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 -1 on failure.
*/
int tis_sendrecv(const uint8_t *sendbuf, size_t send_size, uint8_t *recvbuf,
size_t *recv_len)
{
int res;
unsigned long start;
#ifdef DEBUG
memset(recvbuf, 0xcc, *recv_len);
printf("send to TPM (%d bytes, recv_len=%d):\n", send_size, *recv_len);
print_buffer(0, (void *)sendbuf, 1, send_size, 0);
#endif
res = i2c_write(0x29, 0, 0, (uchar *)sendbuf, send_size);
if (res) {
printf("i2c_write returned %d\n", res);
return -1;
}
start = get_timer(0);
while ((res = i2c_read(0x29, 0, 0, recvbuf, 10))) {
if (get_timer(start) > ATMEL_TPM_TIMEOUT_MS) {
puts("tpm timed out\n");
return -1;
}
udelay(100);
}
if (!res) {
*recv_len = get_unaligned_be32(recvbuf + 2);
if (*recv_len > 10)
res = i2c_read(0x29, 0, 0, recvbuf, *recv_len);
}
if (res) {
printf("i2c_read returned %d (rlen=%d)\n", res, *recv_len);
#ifdef DEBUG
print_buffer(0, recvbuf, 1, *recv_len, 0);
#endif
}
#ifdef DEBUG
if (!res) {
printf("read from TPM (%d bytes):\n", *recv_len);
print_buffer(0, recvbuf, 1, *recv_len, 0);
}
#endif
return res;
}