xref: /openbmc/u-boot/drivers/tpm/tpm-uclass.c (revision afaea1f5)
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 #include <tpm-v1.h>
11 #include <tpm-v2.h>
12 #include "tpm_internal.h"
13 
14 int tpm_open(struct udevice *dev)
15 {
16 	struct tpm_ops *ops = tpm_get_ops(dev);
17 
18 	if (!ops->open)
19 		return -ENOSYS;
20 
21 	return ops->open(dev);
22 }
23 
24 int tpm_close(struct udevice *dev)
25 {
26 	struct tpm_ops *ops = tpm_get_ops(dev);
27 
28 	if (!ops->close)
29 		return -ENOSYS;
30 
31 	return ops->close(dev);
32 }
33 
34 int tpm_get_desc(struct udevice *dev, char *buf, int size)
35 {
36 	struct tpm_ops *ops = tpm_get_ops(dev);
37 
38 	if (!ops->get_desc)
39 		return -ENOSYS;
40 
41 	return ops->get_desc(dev, buf, size);
42 }
43 
44 /* Returns max number of milliseconds to wait */
45 static ulong tpm_tis_i2c_calc_ordinal_duration(struct tpm_chip_priv *priv,
46 					       u32 ordinal)
47 {
48 	int duration_idx = TPM_UNDEFINED;
49 	int duration = 0;
50 
51 	if (ordinal < TPM_MAX_ORDINAL) {
52 		duration_idx = tpm_ordinal_duration[ordinal];
53 	} else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
54 			TPM_MAX_PROTECTED_ORDINAL) {
55 		duration_idx = tpm_protected_ordinal_duration[
56 				ordinal & TPM_PROTECTED_ORDINAL_MASK];
57 	}
58 
59 	if (duration_idx != TPM_UNDEFINED)
60 		duration = priv->duration_ms[duration_idx];
61 
62 	if (duration <= 0)
63 		return 2 * 60 * 1000; /* Two minutes timeout */
64 	else
65 		return duration;
66 }
67 
68 int tpm_xfer(struct udevice *dev, const uint8_t *sendbuf, size_t send_size,
69 	uint8_t *recvbuf, size_t *recv_size)
70 {
71 	struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
72 	struct tpm_ops *ops = tpm_get_ops(dev);
73 	ulong start, stop;
74 	uint count, ordinal;
75 	int ret, ret2;
76 
77 	if (ops->xfer)
78 		return ops->xfer(dev, sendbuf, send_size, recvbuf, recv_size);
79 
80 	if (!ops->send || !ops->recv)
81 		return -ENOSYS;
82 
83 	/* switch endianess: big->little */
84 	count = get_unaligned_be32(sendbuf + TPM_CMD_COUNT_BYTE);
85 	ordinal = get_unaligned_be32(sendbuf + TPM_CMD_ORDINAL_BYTE);
86 
87 	if (count == 0) {
88 		debug("no data\n");
89 		return -ENODATA;
90 	}
91 	if (count > send_size) {
92 		debug("invalid count value %x %zx\n", count, send_size);
93 		return -E2BIG;
94 	}
95 
96 	debug("%s: Calling send\n", __func__);
97 	ret = ops->send(dev, sendbuf, send_size);
98 	if (ret < 0)
99 		return ret;
100 
101 	start = get_timer(0);
102 	stop = tpm_tis_i2c_calc_ordinal_duration(priv, ordinal);
103 	do {
104 		ret = ops->recv(dev, priv->buf, sizeof(priv->buf));
105 		if (ret >= 0) {
106 			if (ret > *recv_size)
107 				return -ENOSPC;
108 			memcpy(recvbuf, priv->buf, ret);
109 			*recv_size = ret;
110 			ret = 0;
111 			break;
112 		} else if (ret != -EAGAIN) {
113 			return ret;
114 		}
115 
116 		mdelay(priv->retry_time_ms);
117 		if (get_timer(start) > stop) {
118 			ret = -ETIMEDOUT;
119 			break;
120 		}
121 	} while (ret);
122 
123 	ret2 = ops->cleanup ? ops->cleanup(dev) : 0;
124 
125 	return ret2 ? ret2 : ret;
126 }
127 
128 UCLASS_DRIVER(tpm) = {
129 	.id             = UCLASS_TPM,
130 	.name           = "tpm",
131 	.flags          = DM_UC_FLAG_SEQ_ALIAS,
132 	.per_device_auto_alloc_size	= sizeof(struct tpm_chip_priv),
133 };
134