xref: /openbmc/u-boot/drivers/tpm/tpm-uclass.c (revision 7da7ff54)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2015 Google, Inc
4  * Written by Simon Glass <sjg@chromium.org>
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <linux/unaligned/be_byteshift.h>
10 #if defined(CONFIG_TPM_V1)
11 #include <tpm-v1.h>
12 #elif defined(CONFIG_TPM_V2)
13 #include <tpm-v2.h>
14 #endif
15 #include "tpm_internal.h"
16 
17 int tpm_open(struct udevice *dev)
18 {
19 	struct tpm_ops *ops = tpm_get_ops(dev);
20 
21 	if (!ops->open)
22 		return -ENOSYS;
23 
24 	return ops->open(dev);
25 }
26 
27 int tpm_close(struct udevice *dev)
28 {
29 	struct tpm_ops *ops = tpm_get_ops(dev);
30 
31 	if (!ops->close)
32 		return -ENOSYS;
33 
34 	return ops->close(dev);
35 }
36 
37 int tpm_get_desc(struct udevice *dev, char *buf, int size)
38 {
39 	struct tpm_ops *ops = tpm_get_ops(dev);
40 
41 	if (!ops->get_desc)
42 		return -ENOSYS;
43 
44 	return ops->get_desc(dev, buf, size);
45 }
46 
47 /* Returns max number of milliseconds to wait */
48 static ulong tpm_tis_i2c_calc_ordinal_duration(struct tpm_chip_priv *priv,
49 					       u32 ordinal)
50 {
51 	int duration_idx = TPM_UNDEFINED;
52 	int duration = 0;
53 
54 	if (ordinal < TPM_MAX_ORDINAL) {
55 		duration_idx = tpm_ordinal_duration[ordinal];
56 	} else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
57 			TPM_MAX_PROTECTED_ORDINAL) {
58 		duration_idx = tpm_protected_ordinal_duration[
59 				ordinal & TPM_PROTECTED_ORDINAL_MASK];
60 	}
61 
62 	if (duration_idx != TPM_UNDEFINED)
63 		duration = priv->duration_ms[duration_idx];
64 
65 	if (duration <= 0)
66 		return 2 * 60 * 1000; /* Two minutes timeout */
67 	else
68 		return duration;
69 }
70 
71 int tpm_xfer(struct udevice *dev, const uint8_t *sendbuf, size_t send_size,
72 	uint8_t *recvbuf, size_t *recv_size)
73 {
74 	struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
75 	struct tpm_ops *ops = tpm_get_ops(dev);
76 	ulong start, stop;
77 	uint count, ordinal;
78 	int ret, ret2;
79 
80 	if (ops->xfer)
81 		return ops->xfer(dev, sendbuf, send_size, recvbuf, recv_size);
82 
83 	if (!ops->send || !ops->recv)
84 		return -ENOSYS;
85 
86 	/* switch endianess: big->little */
87 	count = get_unaligned_be32(sendbuf + TPM_CMD_COUNT_BYTE);
88 	ordinal = get_unaligned_be32(sendbuf + TPM_CMD_ORDINAL_BYTE);
89 
90 	if (count == 0) {
91 		debug("no data\n");
92 		return -ENODATA;
93 	}
94 	if (count > send_size) {
95 		debug("invalid count value %x %zx\n", count, send_size);
96 		return -E2BIG;
97 	}
98 
99 	debug("%s: Calling send\n", __func__);
100 	ret = ops->send(dev, sendbuf, send_size);
101 	if (ret < 0)
102 		return ret;
103 
104 	start = get_timer(0);
105 	stop = tpm_tis_i2c_calc_ordinal_duration(priv, ordinal);
106 	do {
107 		ret = ops->recv(dev, priv->buf, sizeof(priv->buf));
108 		if (ret >= 0) {
109 			if (ret > *recv_size)
110 				return -ENOSPC;
111 			memcpy(recvbuf, priv->buf, ret);
112 			*recv_size = ret;
113 			ret = 0;
114 			break;
115 		} else if (ret != -EAGAIN) {
116 			return ret;
117 		}
118 
119 		mdelay(priv->retry_time_ms);
120 		if (get_timer(start) > stop) {
121 			ret = -ETIMEDOUT;
122 			break;
123 		}
124 	} while (ret);
125 
126 	ret2 = ops->cleanup ? ops->cleanup(dev) : 0;
127 
128 	return ret2 ? ret2 : ret;
129 }
130 
131 UCLASS_DRIVER(tpm) = {
132 	.id             = UCLASS_TPM,
133 	.name           = "tpm",
134 	.flags          = DM_UC_FLAG_SEQ_ALIAS,
135 	.per_device_auto_alloc_size	= sizeof(struct tpm_chip_priv),
136 };
137