2 * Copyright (C) 2013 Guntermann & Drunck, GmbH
4 * Written by Dirk Eibach <eibach@gdsys.de>
6 * SPDX-License-Identifier: GPL-2.0+
12 #include <asm/unaligned.h>
14 #define ATMEL_TPM_TIMEOUT_MS 5000 /* sufficient for anything but
15 generating/exporting keys */
20 * Initialize the TPM device. Returns 0 on success or -1 on
21 * failure (in case device probing did not succeed).
31 * Requests access to locality 0 for the caller. After all commands have been
32 * completed the caller is supposed to call tis_close().
34 * Returns 0 on success, -1 on failure.
44 * terminate the currect session with the TPM by releasing the locked
45 * locality. Returns 0 on success of -1 on failure (in case lock
46 * removal did not succeed).
56 * Send the requested data to the TPM and then try to get its response
58 * @sendbuf - buffer of the data to send
59 * @send_size size of the data to send
60 * @recvbuf - memory to save the response to
61 * @recv_len - pointer to the size of the response buffer
63 * Returns 0 on success (and places the number of response bytes at recv_len)
66 int tis_sendrecv(const uint8_t *sendbuf, size_t send_size, uint8_t *recvbuf,
73 memset(recvbuf, 0xcc, *recv_len);
74 printf("send to TPM (%d bytes, recv_len=%d):\n", send_size, *recv_len);
75 print_buffer(0, (void *)sendbuf, 1, send_size, 0);
78 res = i2c_write(0x29, 0, 0, (uchar *)sendbuf, send_size);
80 printf("i2c_write returned %d\n", res);
85 while ((res = i2c_read(0x29, 0, 0, recvbuf, 10))) {
86 if (get_timer(start) > ATMEL_TPM_TIMEOUT_MS) {
87 puts("tpm timed out\n");
93 *recv_len = get_unaligned_be32(recvbuf + 2);
95 res = i2c_read(0x29, 0, 0, recvbuf, *recv_len);
98 printf("i2c_read returned %d (rlen=%d)\n", res, *recv_len);
100 print_buffer(0, recvbuf, 1, *recv_len, 0);
106 printf("read from TPM (%d bytes):\n", *recv_len);
107 print_buffer(0, recvbuf, 1, *recv_len, 0);