dm: tpm: Add a uclass for Trusted Platform Modules
[karo-tx-uboot.git] / drivers / tpm / tpm-uclass.c
1 /*
2  * Copyright (c) 2015 Google, Inc
3  * Written by Simon Glass <sjg@chromium.org>
4  *
5  * SPDX-License-Identifier:     GPL-2.0+
6  */
7
8 #include <common.h>
9 #include <dm.h>
10 #include <tpm.h>
11 #include <linux/unaligned/be_byteshift.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 };