1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
/* SPDX-License-Identifier: GPL-2.0-or-later */
#include <assert.h>
#include <commonlib/endian.h>
#include <commonlib/helpers.h>
#include <console/console.h>
#include <delay.h>
#include <device/i2c_simple.h>
#include <endian.h>
#include <lib.h>
#include <security/tpm/tis.h>
#include <timer.h>
#include <types.h>
#include "tpm.h"
#define RECV_TIMEOUT (1 * 1000) /* 1 second */
#define XMIT_TIMEOUT (1 * 1000) /* 1 second */
#define SLEEP_DURATION 1000 /* microseconds */
struct tpm_output_header {
uint16_t tag;
uint32_t length;
uint32_t return_code;
} __packed;
static tpm_result_t i2c_tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
uint8_t *recvbuf, size_t *rbuf_len)
{
size_t hdr_bytes;
struct tpm_output_header *header;
size_t max_recv_bytes;
size_t recv_bytes;
int status;
struct stopwatch sw;
ASSERT(sbuf_size >= 10);
if (CONFIG(DRIVER_TPM_DISPLAY_TIS_BYTES)) {
/* Display the TPM command */
if (sbuf_size >= 10)
printk(BIOS_DEBUG, "TPM Command: 0x%08x\n",
read_at_be32(sendbuf, sizeof(uint16_t)
+ sizeof(uint32_t)));
hexdump(sendbuf, sbuf_size);
}
/* Send the command to the TPM */
stopwatch_init_msecs_expire(&sw, XMIT_TIMEOUT);
while (1) {
status = i2c_write_raw(CONFIG_DRIVER_TPM_I2C_BUS,
CONFIG_DRIVER_TPM_I2C_ADDR, (uint8_t *)sendbuf,
sbuf_size);
if ((status < 0) && (!stopwatch_expired(&sw)))
continue;
if (status < 0) {
printk(BIOS_ERR, "I2C write error: %d\n", status);
return TPM_CB_COMMUNICATION_ERROR;
}
break;
}
/* Read the TPM response header */
max_recv_bytes = *rbuf_len;
ASSERT(max_recv_bytes >= sizeof(*header));
hdr_bytes = sizeof(*header);
header = (struct tpm_output_header *)recvbuf;
stopwatch_init_msecs_expire(&sw, RECV_TIMEOUT);
do {
status = i2c_read_raw(CONFIG_DRIVER_TPM_I2C_BUS,
CONFIG_DRIVER_TPM_I2C_ADDR, recvbuf, hdr_bytes);
if (status > 0)
break;
udelay(SLEEP_DURATION);
} while (!stopwatch_expired(&sw));
if (status != sizeof(*header))
return TPM_CB_COMMUNICATION_ERROR;
/* Determine the number of bytes remaining */
recv_bytes = MIN(be32_to_cpu(*(uint32_t *)&header->length),
max_recv_bytes);
/* Determine if there is additional response data */
if (recv_bytes > hdr_bytes) {
/* Display the TPM response */
if (CONFIG(DRIVER_TPM_DISPLAY_TIS_BYTES))
hexdump(recvbuf, hdr_bytes);
/* Read the full TPM response */
status = i2c_read_raw(CONFIG_DRIVER_TPM_I2C_BUS,
CONFIG_DRIVER_TPM_I2C_ADDR, recvbuf, recv_bytes);
if (status < 0) {
printk(BIOS_ERR, "I2C read error: %d\n", status);
return TPM_CB_COMMUNICATION_ERROR;
}
}
/* Return the number of bytes received */
*rbuf_len = status;
/* Display the TPM response */
if (CONFIG(DRIVER_TPM_DISPLAY_TIS_BYTES)) {
printk(BIOS_DEBUG, "TPM Response: 0x%08x\n",
read_at_be32(recvbuf, sizeof(uint16_t)
+ sizeof(uint32_t)));
hexdump(recvbuf, *rbuf_len);
}
/* Successful transfer */
return TPM_SUCCESS;
}
tis_sendrecv_fn i2c_tis_probe(enum tpm_family *family)
{
/*
* Can't query version or really anything as the device doesn't support
* much through this interface (can't specify address on accesses).
*
* Hence the assumption is that whatever TPM version is enabled at
* compile-time defines what the device supports. The check is written
* in a way to give TPM 1 preference even if support for both versions
* is compiled in.
*/
if (family != NULL)
*family = CONFIG(TPM1) ? TPM_1 : TPM_2;
return &i2c_tis_sendrecv;
}
|
