LXR uboot/drivers/tpm/tis

   1/*
   2 * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
   3 * Use of this source code is governed by a BSD-style license that can be
   4 * found in the LICENSE file.
   5 */
   6
   7#include <config.h>
   8#include <common.h>
   9#include <fdtdec.h>
  10#include <i2c.h>
  11#include "slb9635_i2c/tpm.h"
  12
  13DECLARE_GLOBAL_DATA_PTR;
  14
  15/* TPM configuration */
  16struct tpm {
  17        int i2c_bus;
  18        int slave_addr;
  19        char inited;
  20        int old_bus;
  21} tpm;
  22
  23
  24static int tpm_select(void)
  25{
  26        int ret;
  27
  28        tpm.old_bus = i2c_get_bus_num();
  29        if (tpm.old_bus != tpm.i2c_bus) {
  30                ret = i2c_set_bus_num(tpm.i2c_bus);
  31                if (ret) {
  32                        debug("%s: Fail to set i2c bus %d\n", __func__,
  33                              tpm.i2c_bus);
  34                        return -1;
  35                }
  36        }
  37        return 0;
  38}
  39
  40static int tpm_deselect(void)
  41{
  42        int ret;
  43
  44        if (tpm.old_bus != i2c_get_bus_num()) {
  45                ret = i2c_set_bus_num(tpm.old_bus);
  46                if (ret) {
  47                        debug("%s: Fail to restore i2c bus %d\n",
  48                              __func__, tpm.old_bus);
  49                        return -1;
  50                }
  51        }
  52        tpm.old_bus = -1;
  53        return 0;
  54}
  55
  56/**
  57 * Decode TPM configuration.
  58 *
  59 * @param dev   Returns a configuration of TPM device
  60 * @return 0 if ok, -1 on error
  61 */
  62static int tpm_decode_config(struct tpm *dev)
  63{
  64#ifdef CONFIG_OF_CONTROL
  65        const void *blob = gd->fdt_blob;
  66        int node, parent;
  67        int i2c_bus;
  68
  69        node = fdtdec_next_compatible(blob, 0, COMPAT_INFINEON_SLB9635_TPM);
  70        if (node < 0) {
  71                node = fdtdec_next_compatible(blob, 0,
  72                                              COMPAT_INFINEON_SLB9645_TPM);
  73        }
  74        if (node < 0) {
  75                debug("%s: Node not found\n", __func__);
  76                return -1;
  77        }
  78        parent = fdt_parent_offset(blob, node);
  79        if (parent < 0) {
  80                debug("%s: Cannot find node parent\n", __func__);
  81                return -1;
  82        }
  83        i2c_bus = i2c_get_bus_num_fdt(parent);
  84        if (i2c_bus < 0)
  85                return -1;
  86        dev->i2c_bus = i2c_bus;
  87        dev->slave_addr = fdtdec_get_addr(blob, node, "reg");
  88#else
  89        dev->i2c_bus = CONFIG_INFINEON_TPM_I2C_BUS;
  90        dev->slave_addr = CONFIG_INFINEON_TPM_I2C_ADDR;
  91#endif
  92        return 0;
  93}
  94
  95int tis_init(void)
  96{
  97        if (tpm.inited)
  98                return 0;
  99
 100        if (tpm_decode_config(&tpm))
 101                return -1;
 102
 103        if (tpm_select())
 104                return -1;
 105
 106        /*
 107         * Probe TPM twice; the first probing might fail because TPM is asleep,
 108         * and the probing can wake up TPM.
 109         */
 110        if (i2c_probe(tpm.slave_addr) && i2c_probe(tpm.slave_addr)) {
 111                debug("%s: fail to probe i2c addr 0x%x\n", __func__,
 112                      tpm.slave_addr);
 113                return -1;
 114        }
 115
 116        tpm_deselect();
 117
 118        tpm.inited = 1;
 119
 120        return 0;
 121}
 122
 123int tis_open(void)
 124{
 125        int rc;
 126
 127        if (!tpm.inited)
 128                return -1;
 129
 130        if (tpm_select())
 131                return -1;
 132
 133        rc = tpm_open(tpm.slave_addr);
 134
 135        tpm_deselect();
 136
 137        return rc;
 138}
 139
 140int tis_close(void)
 141{
 142        if (!tpm.inited)
 143                return -1;
 144
 145        if (tpm_select())
 146                return -1;
 147
 148        tpm_close();
 149
 150        tpm_deselect();
 151
 152        return 0;
 153}
 154
 155int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
 156                uint8_t *recvbuf, size_t *rbuf_len)
 157{
 158        int len;
 159        uint8_t buf[4096];
 160
 161        if (!tpm.inited)
 162                return -1;
 163
 164        if (sizeof(buf) < sbuf_size)
 165                return -1;
 166
 167        memcpy(buf, sendbuf, sbuf_size);
 168
 169        if (tpm_select())
 170                return -1;
 171
 172        len = tpm_transmit(buf, sbuf_size);
 173
 174        tpm_deselect();
 175
 176        if (len < 10) {
 177                *rbuf_len = 0;
 178                return -1;
 179        }
 180
 181        memcpy(recvbuf, buf, len);
 182        *rbuf_len = len;
 183
 184        return 0;
 185}
 186