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 };