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