1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2013 Guntermann & Drunck, GmbH
4 *
5 * Written by Dirk Eibach <dirk.eibach@gdsys.cc>
6 */
7
8 #include <common.h>
9 #include <dm.h>
10 #include <tpm-v1.h>
11 #include <i2c.h>
12 #include <asm/unaligned.h>
13 #include <linux/delay.h>
14
15 #include "tpm_internal.h"
16
17 #define ATMEL_TPM_TIMEOUT_MS 5000 /* sufficient for anything but
18 generating/exporting keys */
19
20 /*
21 * tpm_atmel_twi_open()
22 *
23 * Requests access to locality 0 for the caller. After all commands have been
24 * completed the caller is supposed to call tis_close().
25 *
26 * Returns 0 on success, -1 on failure.
27 */
tpm_atmel_twi_open(struct udevice * dev)28 static int tpm_atmel_twi_open(struct udevice *dev)
29 {
30 return 0;
31 }
32
33 /*
34 * tpm_atmel_twi_close()
35 *
36 * terminate the currect session with the TPM by releasing the locked
37 * locality. Returns 0 on success of -1 on failure (in case lock
38 * removal did not succeed).
39 */
tpm_atmel_twi_close(struct udevice * dev)40 static int tpm_atmel_twi_close(struct udevice *dev)
41 {
42 return 0;
43 }
44
45 /*
46 * tpm_atmel_twi_get_desc()
47 *
48 * @dev: Device to check
49 * @buf: Buffer to put the string
50 * @size: Maximum size of buffer
51 * @return length of string, or -ENOSPC it no space
52 */
tpm_atmel_twi_get_desc(struct udevice * dev,char * buf,int size)53 static int tpm_atmel_twi_get_desc(struct udevice *dev, char *buf, int size)
54 {
55 return 0;
56 }
57
58 /*
59 * tpm_atmel_twi_xfer()
60 *
61 * Send the requested data to the TPM and then try to get its response
62 *
63 * @sendbuf - buffer of the data to send
64 * @send_size size of the data to send
65 * @recvbuf - memory to save the response to
66 * @recv_len - pointer to the size of the response buffer
67 *
68 * Returns 0 on success (and places the number of response bytes at recv_len)
69 * or -1 on failure.
70 */
tpm_atmel_twi_xfer(struct udevice * dev,const uint8_t * sendbuf,size_t send_size,uint8_t * recvbuf,size_t * recv_len)71 static int tpm_atmel_twi_xfer(struct udevice *dev,
72 const uint8_t *sendbuf, size_t send_size,
73 uint8_t *recvbuf, size_t *recv_len)
74 {
75 int res;
76 unsigned long start;
77
78 #ifdef DEBUG
79 memset(recvbuf, 0xcc, *recv_len);
80 printf("send to TPM (%d bytes, recv_len=%d):\n", send_size, *recv_len);
81 print_buffer(0, (void *)sendbuf, 1, send_size, 0);
82 #endif
83
84 #if !CONFIG_IS_ENABLED(DM_I2C)
85 res = i2c_write(0x29, 0, 0, (uchar *)sendbuf, send_size);
86 #else
87 res = dm_i2c_write(dev, 0, sendbuf, send_size);
88 #endif
89 if (res) {
90 printf("i2c_write returned %d\n", res);
91 return -1;
92 }
93
94 start = get_timer(0);
95 #if !CONFIG_IS_ENABLED(DM_I2C)
96 while ((res = i2c_read(0x29, 0, 0, recvbuf, 10)))
97 #else
98 while ((res = dm_i2c_read(dev, 0, recvbuf, 10)))
99 #endif
100 {
101 /* TODO Use TIS_TIMEOUT from tpm_tis_infineon.h */
102 if (get_timer(start) > ATMEL_TPM_TIMEOUT_MS) {
103 puts("tpm timed out\n");
104 return -1;
105 }
106 udelay(100);
107 }
108 if (!res) {
109 unsigned int hdr_recv_len;
110 hdr_recv_len = get_unaligned_be32(recvbuf + 2);
111 if (hdr_recv_len < 10) {
112 puts("tpm response header too small\n");
113 return -1;
114 } else if (hdr_recv_len > *recv_len) {
115 puts("tpm response length is bigger than receive buffer\n");
116 return -1;
117 } else {
118 *recv_len = hdr_recv_len;
119 #if !CONFIG_IS_ENABLED(DM_I2C)
120 res = i2c_read(0x29, 0, 0, recvbuf, *recv_len);
121 #else
122 res = dm_i2c_read(dev, 0, recvbuf, *recv_len);
123 #endif
124
125 }
126 }
127 if (res) {
128 printf("i2c_read returned %d (rlen=%d)\n", res, *recv_len);
129 #ifdef DEBUG
130 print_buffer(0, recvbuf, 1, *recv_len, 0);
131 #endif
132 }
133
134 #ifdef DEBUG
135 if (!res) {
136 printf("read from TPM (%d bytes):\n", *recv_len);
137 print_buffer(0, recvbuf, 1, *recv_len, 0);
138 }
139 #endif
140
141 return res;
142 }
143
tpm_atmel_twi_probe(struct udevice * dev)144 static int tpm_atmel_twi_probe(struct udevice *dev)
145 {
146 return 0;
147 }
148
149 static const struct udevice_id tpm_atmel_twi_ids[] = {
150 { .compatible = "atmel,at97sc3204t"},
151 { }
152 };
153
154 static const struct tpm_ops tpm_atmel_twi_ops = {
155 .open = tpm_atmel_twi_open,
156 .close = tpm_atmel_twi_close,
157 .xfer = tpm_atmel_twi_xfer,
158 .get_desc = tpm_atmel_twi_get_desc,
159 };
160
161 U_BOOT_DRIVER(tpm_atmel_twi) = {
162 .name = "tpm_atmel_twi",
163 .id = UCLASS_TPM,
164 .of_match = tpm_atmel_twi_ids,
165 .ops = &tpm_atmel_twi_ops,
166 .probe = tpm_atmel_twi_probe,
167 };
168