drivers/tpm/tpm-uclass.c

   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 #define LOG_CATEGORY UCLASS_TPM
   8
   9 #include <common.h>
  10 #include <dm.h>
  11 #include <log.h>
  12 #include <tpm_api.h>
  13 #include <tpm-v1.h>
  14 #include <tpm-v2.h>
  15 #include <dm/lists.h>
  16 #include <linux/delay.h>
  17 #include <linux/unaligned/be_byteshift.h>
  18 #include "tpm_internal.h"
  19
  20 #define TPM_RNG_DRV_NAME        "tpm-rng"
  21
  22 int tpm_open(struct udevice *dev)
  23 {
  24         struct tpm_ops *ops = tpm_get_ops(dev);
  25
  26         if (!ops->open)
  27                 return -ENOSYS;
  28
  29         return ops->open(dev);
  30 }
  31
  32 int tpm_close(struct udevice *dev)
  33 {
  34         struct tpm_ops *ops = tpm_get_ops(dev);
  35
  36         if (!ops->close)
  37                 return -ENOSYS;
  38
  39         return ops->close(dev);
  40 }
  41
  42 int tpm_get_desc(struct udevice *dev, char *buf, int size)
  43 {
  44         struct tpm_ops *ops = tpm_get_ops(dev);
  45
  46         if (!ops->get_desc)
  47                 return -ENOSYS;
  48
  49         return ops->get_desc(dev, buf, size);
  50 }
  51
  52 int tpm_report_state(struct udevice *dev, char *buf, int size)
  53 {
  54         struct tpm_ops *ops = tpm_get_ops(dev);
  55
  56         if (!ops->report_state)
  57                 return -ENOSYS;
  58
  59         return ops->report_state(dev, buf, size);
  60 }
  61
  62 /* Returns max number of milliseconds to wait */
  63 static ulong tpm_tis_i2c_calc_ordinal_duration(struct tpm_chip_priv *priv,
  64                                                u32 ordinal)
  65 {
  66         int duration_idx = TPM_UNDEFINED;
  67         int duration = 0;
  68
  69         if (ordinal < TPM_MAX_ORDINAL) {
  70                 duration_idx = tpm_ordinal_duration[ordinal];
  71         } else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
  72                         TPM_MAX_PROTECTED_ORDINAL) {
  73                 duration_idx = tpm_protected_ordinal_duration[
  74                                 ordinal & TPM_PROTECTED_ORDINAL_MASK];
  75         }
  76
  77         if (duration_idx != TPM_UNDEFINED)
  78                 duration = priv->duration_ms[duration_idx];
  79
  80         if (duration <= 0)
  81                 return 2 * 60 * 1000; /* Two minutes timeout */
  82         else
  83                 return duration;
  84 }
  85
  86 int tpm_xfer(struct udevice *dev, const uint8_t *sendbuf, size_t send_size,
  87         uint8_t *recvbuf, size_t *recv_size)
  88 {
  89         struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
  90         struct tpm_ops *ops = tpm_get_ops(dev);
  91         ulong start, stop;
  92         uint count, ordinal;
  93         int ret, ret2 = 0;
  94
  95         if (ops->xfer)
  96                 return ops->xfer(dev, sendbuf, send_size, recvbuf, recv_size);
  97
  98         if (!ops->send || !ops->recv)
  99                 return -ENOSYS;
 100
 101         /* switch endianess: big->little */
 102         count = get_unaligned_be32(sendbuf + TPM_CMD_COUNT_BYTE);
 103         ordinal = get_unaligned_be32(sendbuf + TPM_CMD_ORDINAL_BYTE);
 104
 105         if (count == 0) {
 106                 log_debug("no data\n");
 107                 return -ENODATA;
 108         }
 109         if (count > send_size) {
 110                 log_debug("invalid count value %x %zx\n", count, send_size);
 111                 return -E2BIG;
 112         }
 113
 114         log_debug("%s: Calling send\n", __func__);
 115         ret = ops->send(dev, sendbuf, send_size);
 116         if (ret < 0)
 117                 return ret;
 118
 119         start = get_timer(0);
 120         stop = tpm_tis_i2c_calc_ordinal_duration(priv, ordinal);
 121         do {
 122                 ret = ops->recv(dev, priv->buf, sizeof(priv->buf));
 123                 if (ret >= 0) {
 124                         if (ret > *recv_size)
 125                                 return -ENOSPC;
 126                         memcpy(recvbuf, priv->buf, ret);
 127                         *recv_size = ret;
 128                         ret = 0;
 129                         break;
 130                 } else if (ret != -EAGAIN) {
 131                         return ret;
 132                 }
 133
 134                 mdelay(priv->retry_time_ms);
 135                 if (get_timer(start) > stop) {
 136                         ret = -ETIMEDOUT;
 137                         break;
 138                 }
 139         } while (ret);
 140
 141         if (ret) {
 142                 if (ops->cleanup) {
 143                         ret2 = ops->cleanup(dev);
 144                         if (ret2)
 145                                 return log_msg_ret("cleanup", ret2);
 146                 }
 147                 return log_msg_ret("xfer", ret);
 148         }
 149
 150         return 0;
 151 }
 152
 153 static int tpm_uclass_post_probe(struct udevice *dev)
 154 {
 155         int ret;
 156         const char *drv = TPM_RNG_DRV_NAME;
 157         struct udevice *child;
 158
 159         if (IS_ENABLED(CONFIG_TPM_RNG)) {
 160                 ret = device_find_first_child_by_uclass(dev, UCLASS_RNG,
 161                                                         &child);
 162
 163                 if (ret != -ENODEV) {
 164                         log_debug("RNG child already added to the TPM device\n");
 165                         return ret;
 166                 }
 167
 168                 ret = device_bind_driver(dev, drv, TPM_RNG_DRV_NAME, &child);
 169                 if (ret)
 170                         return log_msg_ret("bind", ret);
 171         }
 172
 173         return 0;
 174 }
 175
 176 UCLASS_DRIVER(tpm) = {
 177         .id                     = UCLASS_TPM,
 178         .name                   = "tpm",
 179         .flags                  = DM_UC_FLAG_SEQ_ALIAS,
 180 #if CONFIG_IS_ENABLED(OF_REAL)
 181         .post_bind              = dm_scan_fdt_dev,
 182 #endif
 183         .post_probe             = tpm_uclass_post_probe,
 184         .per_device_auto        = sizeof(struct tpm_chip_priv),
 185 };